Eachĭiffraction order consists of two orthogonal polarizations, the In-plane (IP)Īnd Out-of-plane (OP) components. Vious section, but the ports now contains 49 diffraction orders which alsoĪc-counts for a possible rotation of polarization as the wave gets diffracted. The transmitted diffraction orders are not shown as they are all absorbed by the bulk Au substrate. The dark blue curve represents the various diffraction orders in the reflection half space. The light blue curve represents the incident wave and the specular reflec-tion. The model was built as described in theįigure 2.23 : Schematic of the superabsorber illustrating diffraction orders. Numerical simulations were performed using COMSOL Multiphysics to Many diffraction orders between 450–500 nm spectral range, second orderĭiffraction is expected in the 500–750 nm spectral range, and only first order The total number of diffraction orders as a function of wavelength expectedįrom a 2D grating with periodicity of 1500 nm for normal incidence. Of diffraction orders is given by N = (2m max+ 1) × (2n max+ 1). The maximum allowed diffraction order inY isn max=j Λ The maximum allowed diffraction order inXis hencem max=j Λ The grating equation in reflection half space forXcan be written as:Ī similar equation can also be written forY. Unit cell and hence can be considered as a superposition of two 1D gratings The superabsorber shown in Figure 2.23 has a square One can expect diffraction orders toīe present in the 450–950 nm wavelength range due to periodicity of the In this section, we treat the effects of diffractionīoth numerically and experimentally. Num-ber of ports required, which exponentially increases the simulation time.Įx-periment measurements using a fibre based white-light did not detect any Moreover, it isĬomputationally intensive to simulate as diffraction orders increases the The effects of diffraction were hence notĬluded in the numerical simulations mentioned previously. Hence the presence of a substrate suppressesĭiffraction orders. When these periodic resonators are placed near a reflective metal substrate,ĭiffracted beams cancel out due to interference with the reflected diffraction Placing these resonators in a periodic arrangement leads toĭiffraction due to in-phase interactions between distant particles. The MDM superabsorber consists of various resonators in a supercell which
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |